dorsal furrow

例句：

1. 1. The animal's dorsal furrow is visible through the skin.
   动物的背脊线通过皮肤可见。
2. 2.The scientist discovered a dorsal furrow in the fossilized bone.
   科学家在化石骨中发现了一道背脊线。
3. 3.The researchers found that the dorsal furrow was formed by the growth of the plant.
   研究人员发现，植物的生长形成了一道背脊线。